Weeds: Enemy or ally

There's an invasion of noxious weeds on the way as the planet heats up and dries out. Invasive plants could flatten Australia's native vegetation, blowing out current costs of about $8 billion a year. Warnings abound that we don't understand these plants - including from people who say that some weeds can do a good job. Reporter Diane Martin.

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Di Martin: Hello everyone, I'm Di Martin, and today Background Briefing is coming to you from the typical Australian backyard, where I'm spending the next hour digging up the good dirt on weeds.

Now this is a story that spreads well beyond this garden fence, and in quite unexpected ways. There's invading species, dying ecosystems, struggling farmers, and an unholy conflict of interest that some say is bringing Australia to the brink of environmental disaster.

So if you thought weeds were just a vaguely troublesome aspect of gardening, consider the transformer weed.

Di Martin: Rachel McFadyen is Australia's chief weed scientist. Her number one weed is a transformer that's erasing native vegetation from Northern Australia, called Gamba Grass.

Rachel McFadyen: Well it's the worst weed I know of, because when it invades into a woodland grass savannah, it takes out all the native grasses and herbs, and then when it burns, and you're talking about 3 to 4 metre tall grass, when it burns, it kills the trees as well.

Rachel McFadyen says gamba grass is known as 'the green bulldozer'. She's written to the Federal government, warning that graziers are using gamba grass to clear fell trees otherwise protected by land clearing laws.

A major new report on global warming and invasive species says gamba grass will be one of the big winners come climate change, because it uses fire to colonise new territory.

The report's author is Tim Low.

Tim Low: The one that worries me the most is gamba grass and that's because of its capacity to benefit from the expected increase in fire in northern Australia. It is just the most frightening weed I have ever come across in my life.

Di Martin: Yet the seed of gamba grass is being sold and planted by the tonne, and quite legally. Governments haven't declared gamba grass a weed, because some graziers think it's a valuable pasture to fatten their cattle.

Tim Low from the Invasive Species Council.

Tim Low: I mean you are literally playing with fire with this grass; it is just so big. It is a monster, it's a triffid, and it's a flammable triffid.

Di Martin: For those who haven't heard of The Day of the Triffids, it's John Wyndham's best-selling sci fi novel about giant mutant plants that take over the world by sheer weight of numbers and a lethal whip-like stamen.

Attributing weeds with malicious intent is a bit silly. But the impact of these invasive plants is certainly not, and these transformer weeds are cutting a swathe through Australia's landscapes.

The World Wild Life Fund's Andreas Glanznig says Australia's native vegetation is fighting a losing battle.

Andreas Glanznig: I think the one that really struck me was looking at the flood plains of the Victoria River up in the Northern Territory, and just seeing how the flood plain had just been completely changed by mimosa pigra. So you had thickets metres high of this stuff, that had completely changed what was previously sedges, grasses that provided habitat food for the water birds, to just being a big shrub thicket. And that applies with some of the other major weeds such as rubber vine, which was originally an attractive ornamental vine that escaped out of Rockhampton, and has now invaded around about 20% of Queensland, 700,000 hectares, and when you see that stuff just strangle native vegetation around waterways like rivers and so on, you just see what these sort of plants out of place can really do to Australia's environment, and it's quite shocking.

Di Martin: And this is just about weeds in the environment. We haven't even scratched the surface of what's going on down in rural Australia.

Weeds have been a major issue on farms for generations. But there's new attitudes to weeds cropping up in country areas, and later in the program we'll meet a farmer who says we should embrace the weed and be thankful that they're repairing Australia's severely degraded soil. There's just so much more to these weeds than meets the eye.

So why doesn't the public know more about weeds? One survey found just 4% of Australians think it's an important issue.

There is some confusion about what's a weed, and definitions vary. Most say it's a plant out of place that's doing some harm.

But what might be harmful in Queensland might be a prized pot plant in Victoria. And Brisbane-based conservationist, Tim Low says because weeds are green, they don't rate as an environmental issue.

Tim Low: Tree clearing is a very visual thing, you've got really dramatic images of forests being knocked over. When you talk about weed invasion, it's often very pretty plants escaping out of gardens that are choking a forest. It doesn't have the same visual appeal, it doesn't have the same visceral appeal, and there are various other reasons why it doesn't get the run it deserves.

Di Martin: Let's leave Tim Low for a moment, and nip down to Canberra to ask the Federal Minister for Conservation the same question.

Here's pro-logging Tasmanian Senator Eric Abetz.

Eric Abetz: I think it's one of these unfortunate situations where the environmental movement in general terms has dropped the ball in relation to the important environmental issues, and to use the common parlance, that 'weeds ain't sexy', and therefore they don't campaign on that issue. But they'll campaign on forestry where we have a reputation second to none in the world.

Di Martin: A comment sure to raise the hackles of environmentalists around the country.

What's surprising is that back in Brisbane, Tim Low partially agrees.

Tim Low: I mean logging is an extremely important issue, but I have on many occasions criticised greenies for exactly the same issue. It is a real problem. Like I gave a talk to the Wilderness Society last year where I said, Look, you're worried about tree clearing, here is gamba grass its fires kill trees. Here is a weed that will clear trees without bulldozers, you should be really worried about this grass. And they certainly are concerned about it, but that's yet to translate into any policy from them.

Di Martin: Tim Low says the priorities of peak green groups are likely to change as people's main experience of the environment changes. He says people are now more likely to be tramping around a local bit of remnant bush, than a weed-free wilderness.

Tim Low: You've had a shift more towards urban conservation where a lot of bush care groups form in the cities where people get out and care for the bit of bush nearest them, by pulling out weeds. That's the total opposite of wilderness ethos, it's appreciating the wilderness near you.

Di Martin: Groups like the Friends of Mount Majura in Canberra's north. Its co-ordinator is Waltraud Pix.

Waltraud Pix: And the reason why I was starting this park care group, I come from Germany, and for me to settle in such a place with a nature reserve in the back, it was just incredible. I saw that this is a beautiful place on a morning like this with the fog lifting, it's just magic.

Di Martin: Friends of Mount Majura is a small bunch of locals who look after this urban nature reserve in their spare time. They have regular working bees to control soil erosion, plant out natives, and of course, weed.

Waltraud Pix: One of the things we are doing in order to control weeds, and probably the rangers wouldn't do, is we revegetate.

Di Martin: So this is your planting here?

Waltraud Pix: This is one of the planting here; that's apple box, it's a tree which is associated with this ecological community. And so this is a bit of fun, more fun than taking out the weeds.

Di Martin: Waltraud Pix says there's an ongoing supply of weeds to Mount Majura from three main sources. There's ongoing grading work on fire trails and under power lines disturbing the soil. Parts of the mountain were grazed, setting up large seedbanks of intractable pasture weeds. And seeds from nearby gardens are being carried into the reserve by birds.

Waltraud Pix shows off a very impressive pile of dead weeds.

Waltraud Pix: What you see here, these are the vines of honeysuckle, and honeysuckle can really kill other plants because it can grow so densely that nothing else will grow there. I must say honeysuckle, like a few other plants, they are often carried with garden waste into the nature reserve and dumped there. So that is something which I really want people to stop.

Di Martin: People are responsible for weeds. Sometimes we accidentally import weed seed. But mostly, weeds are the unintended result of a search for better pastures and prettier garden plants.

Two-thirds of all weeds come from our backyards. So it stands to reason that's where the next wave of weeds will come from. They're known as sleeper weeds, or referenced weeds, and there's 4-and-half-thousand already in Australia.

The World Wildlife Fund's Biodiversity Policy Manager is Andreas Glanznig.

Andreas Glanznig: If it is a referenced weed, what it means is that it is already playing up somewhere else on earth, and therefore given Australia's broad range of climates, there is a reasonable risk that it could become a problem here. And it's instructive to note that over 3,700 of those are in fact garden plants that are yet to jump the back fence.

Di Martin: So already in our backyards?

Andreas Glanznig: They're already in our backyards, and so what it means is that tomorrow's weeds are already here, and a good portion of those are sitting in backyards ready to go.

Di Martin: What would wake up a sleeper weed is something like a natural disaster, the Hunter Valley floods, for instance. Or a significant shift in our climate.

Rachel McFadyen: Weeds aren't going to lie down and die because climates change. They're actually going to get very much worse. Why are they going to get worse? They're going to get worse because when you stress your natural vegetation, whether it's agriculture, or the natural vegetation, when you stress it and it's not growing so well, something else moves in. And who's best adapted to move in? Someone who produces lots of seeds, has an excellent dispersal mechanism, and grows fast. And that's your local invasive species, your local weed. So whether climate change means we get hotter or we get drier, or we get both, or we get more cyclones, the first to move in are going to be weeds. And that I think you can safely predict.

Di Martin: One of a handful of Australian scientists that's been trying to take the guesswork out of what weeds will do come climate change is Darren Kriticos.

Darren Kriticos: This is the Yarralumla site of ENSIS, it used to be CSIRO's Forests and Forest Products.

Di Martin: Darren Kriticos works in the CSIRO complex in Canberra. He says weeds in northern Australia, carried by stock or on machinery, are about to take a road trip south.

Darren Kriticos: As the climate warms, we're seeing that there's definitely going to be a southward trend in where the weeds can invade to. The tropical weeds and sub-tropical weeds are going to be able to go and enjoy a much broader geographic range in Australia. So those problematic northern weeds, particularly the woody weeds, are going to be able to go and invade a lot further south.

Di Martin: So how are you coming to all of these conclusions about climate change and the spread of weeds? How can you be so sure?

Darren Kriticos: We're using a powerful modelling technique, or package called Climex, developed by CSIRO in the '80s and '90s.

Di Martin: Climex has already been used to work out the potential distribution of weeds.

Now Darren Kriticos is punching in data from the Intergovernmental Panel on Climate Change, and coming up with new global warming weed distribution maps.

The most alarming is the predicted movement of one of Australia's worst weeds, called prickly acacia. It grows in thorny thickets infesting more than 6-million hectares throughout Queensland.

Darren Kriticos.

Darren Kriticos: Here's a map of Australia just looking at the current distribution of prickly acacia centred in the Mitchell grasslands in central Queensland, but spreading off into the Northern Territory. Now we'll go and run a computer simulation here where we run the CSIRO model for the 2080s, and we'll hit the run.

Di Martin: Which is a lightning bolt symbol, which I love.

Darren Kriticos: OK, and as you can see, comparing that original map with the new projected potential distribution -

Di Martin: Of prickly acacia?

Darren Kriticos: Of prickly acacia, you can see that it's getting right down onto the Victorian border and a lot further inland.

Di Martin: The spread is just extraordinary.

Darren Kriticos: Yes, and what this is highlighting for me is that there's going to be an awful lot of farmers in the south who have absolutely no experience with dealing with these woody weeds. In the future they're going to see them.

Di Martin: So prickly acacia coming to a back paddock near you?

Darren Kriticos: It would appear so.

Di Martin: So how is Australia placed to deal with these alarming predictions?

Our national weed management is in its infancy. Just a decade ago, it was essentially each state and territory for itself. Each listed its own weeds, and designed its own strategy for controlling them.

Then in the mid-'90s came the Co-operative Research Centre for Weed Management Systems, or Weeds CRC.

It started co-ordinating research efforts around the country, linking up disparate state departments, universities and other groups. Called 'the envy of agencies worldwide', the Weeds CRC helped get Australia's national weeds policy off the ground. It was the first time Australian governments tackled invasive plants together.

The Weeds CRC also links up all sorts of concerned people, people who don't need a science degree to get involved.

Jane Morton: As a weedspotter, this is the sort of thing we're looking for these new and emerging weeds.

Darryl Saw: Yes, as a weedspotter we're looking for these new weeds ...

Di Martin: Sleeper weeds are waking up all the time. So the CRC set up a program called weedspotters, to help early detection of new invasions.

Under an umbrella in steady Gold Coast rain, weedspotter co-ordinator Jane Morton shows Darryl Saw a new weed she wants him to keep an eye out for.

Jane Morton: This is telegraph weed, heterotheca grandiflora. It's a new weed, amazing, have a look, it's very sticky, want to have a feel of it? Have a look Darryl

Darryl Saw: Yes, you can see that, that's the rosette down there isn't it?

Jane Morton: That's right, yes. And as you can see it's in the daisy family so the seeds are dispersed very easily by wind. And as far as I know, it's on the Spit here, on the Gold Coast, and it's also being dispersed across to the south of South Stradbroke Island, which is a National Park, so it is of concern.

Di Martin: The Weeds CRC has a variety of innovative programs, and helps keep Australia among the four leading countries working on weeds.

But CRC chief Rachel McFadyen says we need to be good, because Australia has one of the worst weed challenges in the world.

Rachel McFadyen: One of the problems Australia has is that we do have the full range of climates; practically every plant there's somewhere in Australia it can grow. So that's a real issue for us. For example, if you were in Britain, you can safely import tropical plants and grow them in your little conservatory, and there's no danger that they're going to become a weed or anything. But for us, well fine if you're in Tasmania, but what if your next move is to Queensland and you take the pot plants with you? That's the problem we have.

Di Martin: Considering the Federal system here, how complex an issue is it to co-ordinate control of weeds, which of course pay absolutely no attention to jurisdictional boundaries?

Rachel McFadyen: It's a nightmare, it's an absolute nightmare.

Di Martin: Surprisingly, the man in charge of weeds at a national level, agrees. Land management belongs to the states, and weeds are a big part of land management.

This is Federal Conservation Minister, Eric Abetz.

Eric Abetz: Legislatively it's very much the state governments' responsibility and local government responsibility as to what can and can't happen thereafter.

Di Martin: What you've described is sounding like a dog's breakfast.

Eric Abetz: Yes, and that is part of the frustrations that we as an Australian government face, unfortunately.

Di Martin: The state at the pointy edge of weed problems is Queensland. It's from here that new weed infestations will head south come climate change. It's also home to some of the most difficult weed conflicts of interest.

TIM LOW FLIPS THROUGH REPORT

Conservationist Tim Low works from his home in Brisbane, where his tables overflow with reports and scientific papers. He says Australia's most potent management weapon against weeds is a scheme called Weeds of National Significance. It gives priority Federal funding to deal with Australia's 20 worst weeds.

But Tim Low says even this system fails when there's a conflict of interest. Like over the tropical pasture grass, hymenachne. It grows in ponds, and was introduced by graziers as a valuable dry season fodder.

Tim Low: When hymenachne was declared a Weed of National Significance, that was back in 1999, there was enormous potential then to stop its spreading. So people knew, the reason it was declared was because it had this enormous potential to go everywhere. Birds were spreading it around really fast, it was washing out of farmers' properties.

Tim Low is on a National Management Committee to control hymenachne, which he says is an abject failure.

Tim Low: Oh, it's really been a disaster. You know, you said to me I'm on that committee and I've asked so many times why am I on a committee that is not doing anything, documenting, total failure, total nothing.

Di Martin: Just describe where that process is falling over?

Tim Low: When it was declared, there should have been funding provided. It wasn't. The funding was prioritised into those Weeds of National Significance that had really high economic impacts. The impacts of hymenachne are environmental, they're social and they're against sugar cane farmers. Sugar cane farmers are not great lobbyists. So it was allowed to get away in the years after it had been declared; it's now just so far beyond control that you wonder what your goals can be.

Di Martin: You've got 3 tiers of government operating against this weed, and they've all failed?

Tim Low: Well I had a weeds officer in the Queensland government say to me quite a few years ago when something really could have been done, he said, Look, at the State level we could ban hymenachne, we could declare it a prohibited weed. It would not work because the actual legal responsibility of carrying out your declaration vests in local government. So what that means is that in those shires where hymenachne grows, the mayor is likely to be a farmer; he is going to tell his weeds officer, Go softly on people growing hymenachne.

Di Martin: How can we ensure as a nation that we don't have a repeat of the hymenachne example?

Tim Low: Well we are having a repeat of that right now, and it's called gamba grass. It's a classic repeat of that; all of the lessons that were so clear. I mean you could just so tangibly see that OK, we've lost on hymenachne, but it has to be the last one. I mean I'm almost in tears to think that it's happening again with gamba grass, that we still haven't learnt anything.

Di Martin: Tim Low's not the only one deeply frustrated by official inaction on gamba grass. Here's Australia's chief weed scientist, Rachel McFadyen.

Rachel McFadyen: I think it's a disgrace. I think that we will be in 50 years time, people are going to be spending big money to get rid of gamba grass which should never have been allowed to be planted in the first place. They've known for at least two to three years that it's a very serious weed, they should have stopped the sale and planting of it then and there.

SOUND OF CATTLE DROVING

Di Martin: The cattle industry is why gamba grass is being actively planted in the Northern Territory, Western Australia, and Queensland, despite all these dire warnings.

A Queensland government report says well-managed gamba grass can feed 40 times more cattle than native grasses. But the same document says cattle won't eat gamba grass when it gets too big, leaving masses of fuel for fires that burn 20 times hotter than normal.

That report, called a Weed Risk Assessment, was completed two years ago. It said the sale of gamba grass should be banned. Yet the report wasn't accepted because of grazier opposition. The man in charge of weed policy recommendations in Queensland is Bruce Wilson. He describes what happened next.

Bruce Wilson: We received some valuable comments then about obtaining additional information particularly on its value as a pasture. So it has been a rather lengthy process in terms of pulling together this additional information.

Bruce Wilson: The negative impact of gamba grass appears to be large, but I think the area of gamba grass in Queensland is still very limited, and limited plantings of it, so .. but ...

Di Martin: But whether or not it's large or not, that does not answer the question of whether graziers are deliberately planting it to circumvent other State legislation.

Bruce Wilson: The actual reason why landholders choose to plant it is something outside of what I can comment on.

Di Martin: About 11 tonnes of gamba grass seed was sold last year, double the quantity sold in previous years. Graziers are trying to get it established on their properties while it's still legal.

Bruce Wilson says a policy recommendation on gamba grass is about to go to the Minister. But Tim Low says the Minister's in-tray is full of weed policy recommendations that go nowhere. Governments have to spend big money on a weed once it's declared. And it's feared that a recent restructure of Queensland's bureaucracy will give more weight to a plant's economic benefit, at the expense of the environment.

The Weeds CRC's Rachel McFadyen makes this frightening assessment of Australia's system of weed management.

Rachel McFadyen: It falls over all the time, as you say. We have very long lists of things that we know are spreading through the country, or spreading through certain environments and nothing is being done about them.

Di Martin: The weeds challenge appears overwhelming. Yet just when awareness of this issue is building, and the campaign to better manage weeds is gathering momentum, came some astonishing news.

Here's the ABC's Landline program.

Sally Sara: But a national research program focused on reducing the impact of weeds is about to be wound down. Prue Adams reports ...

Prue Adams: The Weeds CRC applied to extend its tenure by another seven years, but was knocked back. So, as of the middle of next year, it'll cease to exist.

Di Martin: The Weeds CRC has been funded through the Co-operative Research Council system. Run by the Federal Science Department, the CRC system funds specialised areas of scientific research. But the Federal Minister responsible for weeds is in a different portfolio. Eric Abetz learnt of the funding decision with dismay.

Eric Abetz: The Co-operative Research Centre for Weeds, like all Co-operative Research Centres, had to submit itself to a competitive process and unfortunately it didn't succeed.

Eric Abetz: That is where your listeners can be assured, unfortunate though the result is, that the Co-operative Research Centre funding decisions were not taken on a political basis but by peer review of top scientific people, and they made those determinations on the basis of competitiveness, on merit etc.

Di Martin: However there is a political element to this. Three years ago the former Science Minister, Peter McGauran changed the CRC funding criteria. He put greater emphasis on commercialisation of research, rather than information for the public good.

Yet Rachel McFadyen says the Weeds CRC was still confident enough to spend $300,000 on applying for another round of funding.

Rachel McFadyen: We would not have put all that work in if we'd thought that we could not meet the criteria; we thought we could. The criteria say 'utilisation or commercialisation of research'. Our research is not and never has been commercial in the sense that it produces widgets that can be sold, but it is utilised by farmers and it produces huge commercial benefits for those farmers, and we thought we had demonstrated that very clearly.

Di Martin: There are many in the Howard government who didn't want this cutting-edge CRC to lose its funding. But the Howard government is putting more and more emphasis on science that turns a profit, at the expense of public information.

A shift that endangers Australia's fight against weeds, according to the World Wildlife Fund's Andreas Glanznig.

Andreas Glanznig: Our view is that we're going to return to the dark ages before the CRC program, we're going to see collaborative research decay, we're going to see inefficiencies and duplication creep into Australia's national weed research effort, and I think we're going to lose the value-add of the CRC program, which was enabling researchers in W.A. to be working co-operatively with researchers in New South Wales and so on. And what we'll see is the return to these little sort of State/University/CSIRO fiefdoms, that all do their own thing, don't talk to each other, and ultimately you're going to see a lot less result from the same amount of money.

Di Martin: In the face of these overwhelming challenges, the Federal bureaucracy is struggling to respond.

Co-ordinated national action on weeds is just over ten years old. Some important initial steps have been taken to link up people and ideas across the country.

But efforts are bedevilled by the sheer weight and number of government agencies involved. It's a system described as twice as complicated as the health bureaucracy.

What's easier is educating you, the consumer. A new one-stop national website is being developed; and a radio and print ad campaign is due out in spring.

It targets the increasing number of Australians chasing the semi-rural dream on the edge of towns and cities. Their gardens are the gateway to farms and the bush, and will introduce most of the new wave of sleeper weeds.

John Cotter advises the Federal government on its main weed program. He gives Background Briefing an exclusive peek at a draft of the print ads.

Certainly some of the awareness advertising we'll be doing in the spring will be about showing them pictures of, as we've got here in front of us, Di, the pictures of certain plants and saying, Have you got these plants in your backyard?

Di Martin: Read them out for us here.

John Cotter: Well we've got agapanthus here, lavender, lilies and a variety of grasses.

Di Martin: So you're talking about all of these plants here being weeds?

John Cotter: All of those plants, given the right climatic conditions, planted in the wrong place, can have an invasive impact on our landscape.

Di Martin: The ads ask consumers to check whether the plant they're about to buy could be invasive in their area. It lists a website to visit, or suggests talking to a local plant supplier for more information.

But plants listed in the ads are often big sellers. They are iconic garden plants, drought resistant, easy to grow and propagate.

John Cotter says educating the consumer is the best way to keep nurseries stocking safe plants.

John Cotter: People are driven by demand, and if we educate and inform our householders and our population, and I've got total confidence in the fact that if people are given this information, and let's face it, they haven't been given it before, the majority of people out there will do what is best for the landscape.

Di Martin: But the World Wildlife Fund says this kind of thinking is simply inadequate, and we need much clearer and more accessible information on the threat we face. It says Australia's numerous weed lists should be rolled into one, banning all high risk plants.

For other potential weeds, WWF wants a mandatory warning label. Wherever a plant is sold, it would carry the same information. Which Andreas Glanznig says should include a map of Australia showing where a plant is likely to be weedy.

Andreas Glanznig: When you're about to buy a plant, you can flick the label over: is it invasive? Is it poisonous? And if it is invasive, is it invasive in your region? Yes, or no?

Di Martin: And this would be on the same plastic tag that now exists on plants that you buy from nurseries?

Andreas Glanznig: Totally.

Di Martin: Whose responsibility is it to provide that information, decide which plant's a weed, which plant's invasive and which plant is not?

Andreas Glanznig: Well we'd see that as a joint program between governments, between the industry, and key stakeholders like ourselves, the farmers, the garden clubs of Australia, the scientists, so through the Council of Australasian Weed Societies, for example, that they'd all be brought to the table, and they'd work out a process to come up with a list of weedy plants, to work out which regions they're weedy in, and then to put that information on a label.

Di Martin: Weeds cost Australia $4 billion a year in control efforts and lost production. You can double that amount if you estimate the loss to Australia's environment and biodiversity.

Demands for tougher action are growing. The Weeds CRC chief, Rachel McFadyen, says a system of polluter pays is needed for careless gardeners.

Rachel McFadyen: If you tip chemicals down your driveway and it pollutes your local creek, in most States you will be fined. Now if you dump garden rubbish in the local bush, no one will fine you for it in most cases. They don't regard themselves as having sufficient evidence that it was you that dumped it. And I think we need to say, Look, you're the only people with Cocos Palms in this area, and there's Cocos Palm seeds and plants being dumped in the bush. You're responsible; and fine you for it.

Di Martin: Rachel McFadyen says the same should go for the owners of Australia's growing number of tree plantations. It might come as a shock, but all of the following trees are now declared weeds: Radiata Pine; the Indian neem tree, famous for its medicinal properties. And the olive tree. All are planted on a large scale next to native bush, and all are causing major headaches for the environment. Rachel McFadyen.

Rachel McFadyen: I think the onus should be on the owner of that plantation to clean up the wildlings, before they've had time to set seed and be a problem. But under the current regulations, no, it's the local council, which means the local taxpayer who has to pay.

VINCE HEFFERNAN CALLING DOGS

Di Martin: Down on the farm, they've been battling weeds for as long as stock have been run and crops planted. But there's some interesting new thinking about weeds in rural Australia. Graziers are beginning to see weeds as a part of the diversity of their pastures.

Farmers are less likely to rip up the weeds as they did in the past. It's more common to keep the plant residue of last year's crops on the ground, like a mulch to keep the weeds down, and retain some soil moisture.

And then there's the escalating number of organic and biodynamic farmers who don't use chemical sprays. An international report released this year found Australia has the world's largest land area under organic agriculture, with 11.8 million hectares.

42-year-old Vince Heffernan is a biodynamic farmer from near Crookwell on the New South Wales southern tablelands. We went for a drive to see how he handles his weeds, with the kelpie pup, Sally, preferring to run alongside the ute.

Vince Heffernan: I'm running sheep, both crossbred sheep used for prime lamb production, and some merino sheep for wool production.

Di Martin: When Vince Heffernan took over the family farm five years ago, he moved from conventional to biodynamic production. He didn't know what would happen when he didn't spray his weeds. But it wasn't as bad as he expected. Vince Heffernan says the more fertile his soil is, the less weeds he grows.

Vince Heffernan: We're finding with our grazing management as our soil's coming into balance more with the use of the biodynamic preparations that we're putting out on the soil, the thistles are becoming less of an issue for us. I'm quite convinced of that.

Di Martin: Vince Heffernan also freely admits his weeds have been kept at bay by historically low rainfall, and the release of a successful biocontrol bug that burrows into thistles.

The end of the drought holds mixed blessings for Vince Heffernan. It might revive his parched land, but it will also kick off some astonishing thistle growth.

Vince Heffernan: The variegated thistles the blue thistles, the scotch thistles, saffron thistles, these are the things that you'll see particularly up on these sheep camps on the richer basalt country, and if you can imagine a small plant that might be say the size of the palm of your hand, can spread out and cover something very quickly in a matter of a couple of weeks out to a dinner plate, and eventually out to something as wide as a car tyre, and then as they grow they grow up as well. So you can quite easily drive through a paddock in a car and you can't see the vehicle. They're phenomenally good growers.

Di Martin: Thistles are the weed bane of Vince Heffernan's farming life. But there's one man who says Vince should be grateful for every thistle on his property.

That's Hunter Valley farmer and horse breeder, Peter Andrews.

Now prepare yourselves. Everything you've heard so far about weeds is that they're negative. But Peter Andrews says weeds, in a managed ecosystem like a farm, can be an ally, not an enemy. And his ideas have attracted praise from top scientists, and high political office.

'AUSTRALIAN STORY' THEME

Di Martin: You might remember Peter Andrews from a double episode of the ABC's 'Australian Story' program, how he turned a degraded horse stud into the envy of the Hunter Valley.

Peter Andrews: I realised 30 years ago that there was a major threat. We've failed to recognise in this country that it had some unique qualities that made it sustainable in its own right. Biodiversity, and the ability to prevent water evaporating, they were the really simple things.

Di Martin: Central to Peter Andrews' ideas are that Australia's ancient and fragile soils are very low in carbon, and need plant cover all the time.

Weeds grow in degraded or disturbed soil. Their thorns or unpalatable taste keep stock from doing more damage to that soil. Weeds stabilise the soil. And because they're not eaten, 100% of their plant residue returns to the soil when they die.

One of Peter Andrews' supporters is a member of the Wentworth Group of scientists and a former CSIRO Head of Land and Water. His name is John Williams, and he explains a weed is like nature's paramedic.

John Williams: What Peter Andrews often talks about, and I think ecologically, in my judgement, is very well founded, that the weed species can actually begin the healing process. Weeds can be a sign of a wound in the landscape being repaired, and it's a matter of, just like when we look at a scab on a wound. We don't want the scab there forever, but that scab plays a very important role in bringing healing.

Di Martin: That's John Williams.

Peter Andrews goes much further and is full of praise for weedy plants. He says it's a good thing that many farm weeds have broad leaves and a deep tap root.

Peter Andrews: They grow a huge surface area, green surface area, pump sugars into the ground to feed bacteria to win minerals out of the soil, apart from chasing the ones that have leached, so that they're a real trigger to soil processing.

Di Martin: Peter Andrews says stock will eat some dead weeds, after the thorns have softened and the tannins broken down. And there's more. Through decades of observation, he's convinced that weeds naturally progress to pasture.

Peter Andrews says many farm weeds grow a tremendous amount in a short life cycle. That means a lot of organic matter or carbon, returned to the soil for free, and very quickly. The more carbon, the more fertility. The higher the fertility, the less weeds.

He suggests an experiment for sceptical farmers.

Peter Andrews: If he's frightened about his paddock, go to an area where a lot of weeds already exist. It need only be 12 feet square or less. Tell him to put every weed that he's got and a handful of his pasture seed in there, and then conduct an experiment. He can do whatever he likes, fertilise it, water it, but he only recycles it, in other words, mows it and keeps the residue in situ.

Di Martin: That organic matter forms a mulch, which Peter Andrews says only grass can pierce.

Peter Andrews: Because grass in that mulch that's been created, is much more competitive than any weed can be. See a weed comes up first with two big broad leaves and as soon as you've got mulch on the ground, they can't push through. But grass, with a little fine blade like it's got, can come through mulch. And that's very basic.

Di Martin: There are two more things to keep in mind. You've got to make sure this increased fertility is not being leached away, which would keep the weed cycle going.

So Peter Andrews says get as much carbon as you can to whatever high ground you have, so inground water movement will feed that fertility downhill.

His ideas are challenging. But Peter Andrews says if we can send a rocket to the moon, then we must have the know-how to mulch gorse in Tasmania, or lantana in Queensland, and return desperately needed carbon to the soil

CAR PULLS UP

An hour's drive out of Canberra, there's a major trial of Peter Andrews' ideas.

Tony Coote: Welcome to Mulloon Creek Natural Farms, I'm Tony Coote. And what this is, is to efficiently and effectively provide a practical learning experience in the Peter Andrews' method, clarifying the Australian landscape functions ...

Di Martin: A capacity crowd is here to learn about the system of 'Natural Sequence Farming'.

Here, Peter Andrews listens to a question from a man who fenced off his spring, and watched an explosion of blackberries set in.

Man: This particular area is a spring area, a natural spring, that's why we locked it up, to keep the cattle out of the spring because it flows perpetually, and it's just getting overrun with blackberries.

Peter Andrews: You said the cattle were going to wreck the spring, you know, and you're exactly right, no question. What the blackberry did back in Europe where the spring situation occurred, was occupy exactly that area and keep the cattle off it and stop wrecking the spring. So it's actually doing what it was intended to do, and it's now moved into this landscape to protect areas that it would have normally been protecting in Europe.

Di Martin: Blackberries are such a persistent and difficult problem in Australia, it's hard to think they can do anything worthwhile. But Peter Andrews says these plants out of place not only protect the soil, but fertilise it with leaves and other plant residue. Then the increased fertility is fed by the spring further downhill.

He argues in a managed ecosystem like a farm, you can use the blackberry, while stopping it from getting away.

Peter Andrews: Keep the blackberry mulched and so on into its heap, and the more blackberry mulch you get in that area, the less it will grow.

Di Martin: Peter Andrews is often asked whether there's a native plant that can do the same thing. He says rather than incur the cost and effort of finding the right plant, buying it, planting it out, and then waiting for it to slowly do the same service, farmers should use what's already growing on their land for free, and then manage the weed to stop it spreading.

Peter Andrews: The first thing, stop the landscape dying, most of the things we can then do once plants have stopped it dying, can be adjusted. It's not a big deal. These plants that we're carrying on about, produce millions of seeds n a couple of years, they've been here for 100 years. You're never going to get rid of them. So what we need to know is how cheaply and how effectively we can use a management strategy. I'm not saying not to manage them, ever.

Di Martin: Background Briefing put Peter Andrews' ideas to the acid test, and went and asked two local farmers at the Field Day whether they were persuaded by what he had to say.

This is Ann Synnot and her neighbour, Peter White.

Peter White: I can't say that I would just go home and if I see a Paterson's Curse growing just inside the gate that I won't kick it out, I can guarantee you.

Di Martin: Is anything he's saying now persuading you?

Ann Synott: Yes, it's more what I'm seeing as well, I mean the fact that there is grass growing in the gully and that he says it will come up the banks, it probably will because the thistles are not growing in the gully. That's a proof to me.

Di Martin: And so is it something that you think Australian farmers should be having a listen to?

Ann Synott: Oh, definitely, but it will take a lot of persuading a lot of them.

Di Martin: The Mulloon Creek trial is being sponsored by a government land management agency in New South Wales, known as the Catchment Management Authority.

Noel Kesby is General Manager of the Southern Rivers CMA.

Noel Kesby: Obviously there are some issues with certain types of weeds that the community are not ready to accept. But I think the issue is, we've had most of these weeds in our landscape for nearly 200 years, and we've been throwing repairs and chemicals and controls at them for 200 years, and they're still here. What we in the CMA are trying to get a grip of, is total vegetation management, total groundcover management, and if weeds are part of the colonising initial cover while we establish more beneficial plants, particularly natives, then we want to be involved and see how they work. So because this is a fully endorsed trial and it's fully scientifically managed and measured, other CMAs are looking at that.

Di Martin: So there's some interest in this experiment here?

Noel Kesby: Definitely, a lot of interest, both locally where we are and in our CMA area, plus all over the State.

Di Martin: The idea that weeds can be an ally not an enemy, is gaining ground. But what might work on a farm, might not apply in Australia's struggling bush.

Former CSIRO Head of Land and Water, John Williams, says there are many invasive exotic plants outcompeting the natives.

John Williams: We therefore recognise we've changed the system, now we've got to try and manage it, back to a system that provides the habitat for the biodiversity that we want to encourage in our National Parks.

Di Martin: So we can't rely on nature to provide the succession?

John Williams: Well not in Australia, when we've brought in something that's been no natural predator, no natural competitor for, we've suddenly got an ecosystem that's going to take quite a long time before it actually can re-establish the diversity that it once had.

Di Martin: I suppose the upshot to Peter Andrews' quite provocative thoughts and ideas, is does Australia have a reasonably undifferentiated kneejerk reaction to weeds, that they should be eradicated at any cost?

John Williams: Yes, I think that we need a more balanced and an ecological analysis of what's going on. Ecosystems have a diversity of species in there. Some of those species are weed species. They have a role in the ecosystem's dynamic nature and function. But we're in that ecosystem too. There are also some driving forces of nature that we need to work with, not against.

Di Martin: We've only just scratched the surface in understanding how the soil works, how plants react to change, and the true extent of our impact on the environment.

Chief of the Weed CRC, Rachel McFadyen says we need to get much smarter, and do a lot better than we have in the past.

Rachel McFadyen: Well obviously the largest and most serious invasive species on this planet is human beings. We are the ones that are invading everywhere and destroying an awful lot. Most of these weeds were brought in by us, and we're not now managing them properly, and we have a responsibility to do that.